Selecting Indicators to Evaluate Soil Quality
The main degraded and contaminated soils in Taiwan include highly acid soils, soils deficient in micro-elements, eroded and poorly drained sandy soils, soils suffering from water stress, compacted soils, and rural soils contaminated by trace elements and organic pollutants. Reliable and practical indicators of soil quality are needed to evaluate the condition of degraded and polluted soils. In this Bulletin, several indicators are selected for soil quality assessment in sustainable soil management systems, based on the concept of the control chart. The critical level (threshold level, an upper control limit (UCL), and a lower control limit (LCL)) represent the values within which soil quality must be kept for sustainable soil management.